Current state of knowledge on TRALI pathophysiology, diagnostics and prevention

Abstract

Transfusion-related acute lung injury (TRALI) is the leading cause of mortality following transfusion of blood components. Characteristic for TRALI is acute hypoxemia during or up to 6h after transfusion provided that cardiogenic respiratory failure and transfusion-associated circulatory overload (TACO) are excluded.

In this article we present: 1) Etiology and pathomechanism of TRALI syndrome including the numerous issues that are still unresolved. Currently accepted is the multiple-event model which involves both the patient and the transfused blood components. The TRALI syndrome may be either immunological or nonimmunological dependant on the various factors that activate neutrophils – the main cells in TRALI pathogenesis. 2) TRALI diagnosis should be based mainly on the clinical presentation due to the variety of pathomechanism of the syndrome; however testing of anti-leukocyte antibodies in transfused blood components, according to ISBT guidelines, is recommended in order to prevent TRALI incidence. 3) Different strategies of TRALI prevention, although up to date no ultimate provisions have been accepted. Transfusion of plasma collected only from men seems to be a promising solution as in many countries that adapted this preventive measure the number of TRALI cases has substantially decreased. 4) Different methods of proceeding with donors who donated blood components that were the cause of TRALI in transfused patients. It still remains an open question whether to defer donors with anti-leukocyte antibodies or multi pregnant women.